1. Field
This application relates generally to the field of corneal implants. For example, this application is directed to corneal inlays with an aperture to improve depth of focus (e.g. “masked” corneal inlays) and methods of making.
2. Description of the Related Art
The human eye functions to provide vision by transmitting and focusing light through a clear outer portion called the cornea, and further refining the focus of the image by way of a crystalline lens onto a retina. The quality of the focused image depends on many factors including the size and shape of the eye, and the transparency of the cornea and the lens.
The optical power of the eye is determined by the optical power of the cornea and the crystalline lens. In a normal, healthy eye, sharp images of distant objects are formed on the retina (emmetropia). In many eyes, images of distant objects are either formed in front of the retina because the eye is abnormally long or the cornea is abnormally steep (myopia), or formed in back of the retina because the eye is abnormally short or the cornea is abnormally flat (hyperopia). The cornea also may be asymmetric or toric, resulting in an uncompensated cylindrical refractive error referred to as corneal astigmatism.
A normally functioning human eye is capable of selectively focusing on either near or far objects through a process known as accommodation. Accommodation is achieved by inducing deformation in a lens located inside the eye, which is referred to as the crystalline lens. Such deformation is induced by muscles called ciliary muscles. In most individuals, the ability to accommodate diminishes with age and these individuals cannot see up close without vision correction. If far vision also is deficient, such individuals are usually prescribed bifocal lenses.